The present invention relates to a knee airbag or kneebag for restraining knees of an occupant so that a lower body of the occupant does not move toward a front side of a vehicle to prevent lower legs of the occupant from striking against an interior panel in front of a seat in an event of a collision of the vehicle, and also relates to an occupant leg protection system including the kneebag.
As an occupant leg protection system for protecting lower legs of an occupant from striking against an interior panel in front of a seat and from receiving a large load in an event of a head-on collision of a high-speed vehicle such as a car, there has been a system including a kneebag to be inflated in front of the occupant legs and an inflator (gas generator) for inflating the kneebag.
Japanese Patent Publication (Kokai) No. 11-321539 has disclosed an occupant leg protection system in which a kneebag is inflated in a region of an instrument panel facing occupant knees, so that the inflated kneebag receives the occupant knees, thereby restraining a forward movement of the occupant body. When the inflated kneebag receives the occupant knees in such a way, it is possible to prevent the forward movement of the occupant body effectively.
In general, a glove box (glove compartment) and the like is provided in a region of an instrument panel at a height facing the occupant knees. Accordingly, it is sometimes difficult to dispose an occupant leg protection system in the region. Accordingly, an occupant leg protection system may be disposed below the region (height lower than the region facing the occupant knees), so that a kneebag is inflated upwardly from below to deploy toward the height facing the occupant knees.
However, in such a structure, it is necessary to inflate the kneebag upwardly from below over a relatively long distance from a height lower than the occupant knees to a height facing the knees, thereby making the kneebag large. It is also necessary to use a high-output inflator to inflate the large kneebag quickly.
In view of the problems described above, an object of the present invention to provide a kneebag to be quickly inflated upwardly from below without a high-output inflator, and an occupant leg protection system including the kneebag.
Further objects and advantages of the invention will be apparent from the following description of the invention.